1. Field of the Invention
The present invention relates to monitor device and more particularly to a device for monitoring a motor vehicle""s electric power (including a battery and an alternator or charger) and method therefor.
2. Description of Related Art
A conventional battery (e.g., NP battery) has a characteristic curve as shown in FIG. 9 wherein the smaller the discharge current the longer time the stable output voltage will be. Also, both ambient temperature and storage time affect the available power of battery as indicated by graphs of FIGS. 10 and 11 respectively. Moreover, a useful life of battery is mainly affected by ambient temperature, charging technique and time, and discharge technique. In addition, prior art does not provide a way to inform driver about the status of battery in a near real time basis. Typically, driver inspects battery only when it is abnormally low. As to a faulty alternator, it is typical for a driver to contact a technician for assistance. This is not convenient especially in an emergency. Thus improvement exists.
It is an object of the present invention to provide a device for monitoring a motor vehicle""s electric power and method therefor. The method comprises sampling, calculating, comparing, displaying result, and counting interval. The device comprises a stabilizing circuit, a CPU, a voltage sampling circuit, a current control circuit, and a color lamp display circuit. The invention can inform driver about status of battery by consuming very little power.
The above and other objects, features and advantages of the present invention will become apparent from the following detailed description taken with the accompanying drawings.